Fallbrook district plans to market sludge

FALLBROOK -- A plan to save money by recycling sludge into
fertilizer may be up and running by the end of July, Fallbrook
Public Utility District officials said last week.

The district has installed most of the equipment needed to dry
sludge at its sewer treatment plant off Alturas Road, an
undertaking that involves machinery worth more than a million
dollars, but it will save the district even more in the long run,
General Manager Keith Lewinger said.

Sludge is the semisolid, slushy matter that remains after sewage
is treated. The Fallbrook district now pays about $150,000 a year
to haul the heavy, wet stuff to a site in Riverside County, but
that price is expected to skyrocket in the next few years, after
the Riverside County facility shuts down, Lewinger said. The next
closest site is in Kern County.

By drying the sludge on its own, the district should be able to
cut costs or at least maintain its current level of spending when
dealing with sludge, Lewinger said.

He said the most conservative estimate is that by using the new
equipment, the district would spend $150,000 a year to dry the
sludge and transport it to a landfill. Even in that case, the
drying equipment will pay for itself within seven years because the
district won't have to absorb the increasing costs of hauling wet
sludge, he added.

The fiscal picture could get even better if the district is able
to sell the sludge as district officials have planned.

Lewinger said the most likely scenario for the district is "that
we're going to be able to execute a contract with a fertilizer
packager who will buy this stuff from us, rather than us having to
dispose of it."

The chemicals and natural gas needed to run the drying equipment
will cost about $75,000 a year, Lewinger said.

Trucking the dry product to a landfill would cost around
$85,000, he estimated, but if the district can find a buyer, the
revenue would help offset the cost of operating the new
equipment.

Almost built

The drying facility is being assembled at the district's Alturas
Road property and is awaiting three pieces of equipment before it
can begin operating, said Mike Page, engineering manager.

During a tour of the site on Wednesday, Page explained how the
process will work, naming a dozen different machines all hooked
together in an engineer's playground of sorts covered by a
roof.

The sludge will be dehydrated a little bit before it is put into
the dryer, where "thermal fluid" -- a type of oil -- will be heated
to 480 degrees and run through pipes inside the machine, Page said.
A turbine will burn natural gas bought from San Diego Gas &
Electric Co. in order to heat the oil.

The heat that radiates from the superheated oil will dry the
sludge completely and kill all harmful pathogens, producing sterile
granules or pellets that the district hopes to sell as fertilizer,
he said.